本地eclipse java api连接远程虚拟机HBase

1.本地与远程连通

无论是域名或者ip都可以,另外需保证HBase在虚拟机集群上正常运行。

2.本地要有一个跟远程相同的hadoop环境

当然不相同,只要兼容也可以,现采用hadoop-2.5.0-cdh5.3.6,此版本如果在Windows系统中。在java api调用时候会报错Could not locate executable D:\Hu_software\hadoop-2.5.0-cdh5.3.6\bin\winutils.exe in the Hadoop bina
此时可以从别的拷贝一个winutils.exe到此bin来。可从winutls.exe下载,提取吗wt9x。经测试用hadoop-2.7.7也可以测试跑通,下载解压即可。

3.代码运行前准备

首先需要HADOOP_HOME的环境变量,可以配置到系统环境变量里面,也可以如下:

Eclipse->Debug/Run Configurations -> Environment (tab) -> and added

variable: HADOOP_HOME

Value: C:\hadoop-2.5.0-cdh5.3.6

最好配以log4j.properties到src目录下面,地址。

4.启动执行

(1) pom.xml

 <dependency>
    <groupId>org.apache.hbase</groupId>
    <artifactId>hbase-server</artifactId>
    <version>0.98.6-hadoop2</version>
 </dependency>

 <dependency>
    <groupId>org.apache.hbase</groupId>
    <artifactId>hbase-client</artifactId>
    <version>0.98.6-hadoop2</version>
 </dependency>

(2)java 代码 HBaseDemo.java

package com.hoult.hbase;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.Cell;
import org.apache.hadoop.hbase.CellUtil;
import org.apache.hadoop.hbase.HBaseConfiguration;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MasterNotRunningException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.ZooKeeperConnectionException;
import org.apache.hadoop.hbase.client.Delete;
import org.apache.hadoop.hbase.client.HBaseAdmin;
import org.apache.hadoop.hbase.client.HTable;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.util.Bytes;

public class HBaseDemo {
    //创建Hadoop以及HBased管理配置对象
    public static Configuration conf;
    
    static{
        //使用HBaseConfiguration的单例方法实例化
        conf = HBaseConfiguration.create();
        conf.set("hbase.rootdir","hdfs://hadoop-senior01.hoult.com:9000/hbase");//可以吧hadoop改成你的域名或Ip
        conf.set("hbase.zookeeper.quorum","hadoop-senior01.hoult.com,hadoop-senior02.hoult.com,hadoop-senior03.hoult.com");  //hbase 服务地址
        conf.set("hbase.zookeeper.property.clientPort","2181"); //端口号默认2128不用改
    }
    
    /**
     * 判断表是否已存在
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static boolean isTableExist(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        //在HBase中管理、访问表需要先创建HBaseAdmin对象
        HBaseAdmin admin = new HBaseAdmin(conf);
        return admin.tableExists(tableName);
    }
    
    /**
     * 创建表
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static void createTable(String tableName, String... columnFamily) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        HBaseAdmin admin = new HBaseAdmin(conf);
        //判断表是否存在
        if(isTableExist(tableName)){
            System.out.println("表" + tableName + "已存在");
            //System.exit(0);
        }else{
            //创建表属性对象,表名需要转字节
            HTableDescriptor descriptor = new HTableDescriptor(TableName.valueOf(tableName));
            
            //创建多个列族
            for(String cf : columnFamily){
                descriptor.addFamily(new HColumnDescriptor(cf));
            }
            
            //根据对表的配置,创建表
            admin.createTable(descriptor);
            System.out.println("表" + tableName + "创建成功!");
        }
    }
    
    /**
     * 删除表
     * @param args
     * @throws IOException 
     * @throws ZooKeeperConnectionException 
     * @throws MasterNotRunningException 
     */
    public static void dropTable(String tableName) throws MasterNotRunningException, ZooKeeperConnectionException, IOException{
        HBaseAdmin admin = new HBaseAdmin(conf);
        if(isTableExist(tableName)){
            admin.disableTable(tableName);
            admin.deleteTable(tableName);
            System.out.println("表" + tableName + "删除成功!");
        }else{
            System.out.println("表" + tableName + "不存在!");
        }
        
    }
    
    /**
     * 向表中插入数据
     * @param tableName
     * @param rowKey
     * @param columnFamily
     * @param column
     * @param value
     * @throws IOException 
     */
    public static void addRowData(String tableName, String rowKey, String columnFamily, String column, String value) throws IOException{
        //创建HTable对象
        HTable hTable = new HTable(conf, tableName);
        //向表中插入数据
        Put put = new Put(Bytes.toBytes(rowKey));
        //向Put对象中组装数据
        put.add(Bytes.toBytes(columnFamily), Bytes.toBytes(column), Bytes.toBytes(value));
        hTable.put(put);
        hTable.close();
        System.out.println("插入数据成功");
    }
    
    /**
     * 删除多行数据
     * @param tableName
     * @param rows
     * @throws IOException 
     */
    public static void deleteMultiRow(String tableName, String... rows) throws IOException{
        HTable hTable = new HTable(conf, tableName);
        List<Delete> deleteList = new ArrayList<Delete>();
        for(String row : rows){
            Delete delete = new Delete(Bytes.toBytes(row));
            deleteList.add(delete);
        }
        hTable.delete(deleteList);
        hTable.close();
    }
    
    /**
     * 得到所有的数据
     * @param tableName
     * @throws IOException 
     */
    public static void getAllRows(String tableName) throws IOException{
        HTable hTable = new HTable(conf, tableName);
        //得到用于扫描region的对象
        Scan scan = new Scan();
        //使用HTable得到resultcanner实现类的对象
        ResultScanner resultScanner = hTable.getScanner(scan);
        for(Result result : resultScanner){
            Cell[] cells = result.rawCells();
            for(Cell cell : cells){
                //得到rowkey
                System.out.print(Bytes.toString(CellUtil.cloneRow(cell)) + "\t");
                //得到列族
                System.out.print(Bytes.toString(CellUtil.cloneFamily(cell))+ "\t");
                System.out.print(Bytes.toString(CellUtil.cloneQualifier(cell))+ "\t");
                System.out.println(Bytes.toString(CellUtil.cloneValue(cell))+ "\t");
            }
        }
        
    }
    
    public static void main(String[] args) {
            try {
//              System.out.println(isTableExist("student"));
//              createTable("person", "basic_info", "job", "heathy");
//              dropTable("person");
                addRowData("person", "1002", "basic_info", "name", "Hoult");
                addRowData("person", "1003", "basic_info", "sex", "Male");
                addRowData("person", "1002", "basic_info", "age", "22");
                addRowData("person", "1004", "job", "dept_no", "123");
//              
//              deleteMultiRow("person", "person");
//              getAllRows("person");
                
            } catch (Exception e) {
                e.printStackTrace();
            }
    }

}

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转载自www.cnblogs.com/DarrenHu/p/bigdata_hbase.html